/*
 * Copyright © 2015 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

/* A collection of unit tests for cache.c */

#include <gtest/gtest.h>

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <ftw.h>
#include <errno.h>
#include <stdarg.h>
#include <inttypes.h>
#include <limits.h>
#include <time.h>
#include <unistd.h>

#include "util/mesa-sha1.h"
#include "util/disk_cache.h"
#include "util/ralloc.h"

#ifdef ENABLE_SHADER_CACHE

/* Callback for nftw used in rmrf_local below.
 */
static int
remove_entry(const char *path,
             const struct stat *sb,
             int typeflag,
             struct FTW *ftwbuf)
{
   int err = remove(path);

   if (err)
      fprintf(stderr, "Error removing %s: %s\n", path, strerror(errno));

   return err;
}

/* Recursively remove a directory.
 *
 * This is equivalent to "rm -rf <dir>" with one bit of protection
 * that the directory name must begin with "." to ensure we don't
 * wander around deleting more than intended.
 *
 * Returns 0 on success, -1 on any error.
 */
static int
rmrf_local(const char *path)
{
   if (path == NULL || *path == '\0' || *path != '.')
      return -1;

   return nftw(path, remove_entry, 64, FTW_DEPTH | FTW_PHYS);
}

static void
check_directories_created(void *mem_ctx, const char *cache_dir)
{
   bool sub_dirs_created = false;

   char buf[PATH_MAX];
   if (getcwd(buf, PATH_MAX)) {
      char *full_path = ralloc_asprintf(mem_ctx, "%s%s", buf, ++cache_dir);
      struct stat sb;
      if (stat(full_path, &sb) != -1 && S_ISDIR(sb.st_mode))
         sub_dirs_created = true;
   }

   EXPECT_TRUE(sub_dirs_created) << "create sub dirs";
}

static bool
does_cache_contain(struct disk_cache *cache, const cache_key key)
{
   void *result;

   result = disk_cache_get(cache, key, NULL);

   if (result) {
      free(result);
      return true;
   }

   return false;
}

static bool
cache_exists(struct disk_cache *cache)
{
   uint8_t key[20];
   char data[] = "some test data";

   if (!cache)
      return false;

   disk_cache_compute_key(cache, data, sizeof(data), key);
   disk_cache_put(cache, key, data, sizeof(data), NULL);
   disk_cache_wait_for_idle(cache);
   void *result = disk_cache_get(cache, key, NULL);

   free(result);
   return result != NULL;
}

#define CACHE_TEST_TMP "./cache-test-tmp"

static void
test_disk_cache_create(void *mem_ctx, const char *cache_dir_name)
{
   struct disk_cache *cache;
   int err;

   /* Before doing anything else, ensure that with
    * MESA_SHADER_CACHE_DISABLE set to true, that disk_cache_create returns NULL.
    */
   setenv("MESA_SHADER_CACHE_DISABLE", "true", 1);
   cache = disk_cache_create("test", "make_check", 0);
   EXPECT_EQ(cache, nullptr) << "disk_cache_create with MESA_SHADER_CACHE_DISABLE set";

   unsetenv("MESA_SHADER_CACHE_DISABLE");

#ifdef SHADER_CACHE_DISABLE_BY_DEFAULT
   /* With SHADER_CACHE_DISABLE_BY_DEFAULT, ensure that with
    * MESA_SHADER_CACHE_DISABLE set to nothing, disk_cache_create returns NULL.
    */
   unsetenv("MESA_SHADER_CACHE_DISABLE");
   cache = disk_cache_create("test", "make_check", 0);
   EXPECT_EQ(cache, nullptr)
      << "disk_cache_create with MESA_SHADER_CACHE_DISABLE unset "
         "and SHADER_CACHE_DISABLE_BY_DEFAULT build option";

   /* For remaining tests, ensure that the cache is enabled. */
   setenv("MESA_SHADER_CACHE_DISABLE", "false", 1);
#endif /* SHADER_CACHE_DISABLE_BY_DEFAULT */

   /* For the first real disk_cache_create() clear these environment
    * variables to test creation of cache in home directory.
    */
   unsetenv("MESA_SHADER_CACHE_DIR");
   unsetenv("XDG_CACHE_HOME");

   cache = disk_cache_create("test", "make_check", 0);
   EXPECT_NE(cache, nullptr) << "disk_cache_create with no environment variables";

   disk_cache_destroy(cache);

#ifdef ANDROID
   /* Android doesn't try writing to disk (just calls the cache callbacks), so
    * the directory tests below don't apply.
    */
   return;
#endif

   /* Test with XDG_CACHE_HOME set */
   setenv("XDG_CACHE_HOME", CACHE_TEST_TMP "/xdg-cache-home", 1);
   cache = disk_cache_create("test", "make_check", 0);
   EXPECT_FALSE(cache_exists(cache))
      << "disk_cache_create with XDG_CACHE_HOME set with a non-existing parent directory";

   err = mkdir(CACHE_TEST_TMP, 0755);
   if (err != 0) {
      fprintf(stderr, "Error creating %s: %s\n", CACHE_TEST_TMP, strerror(errno));
      GTEST_FAIL();
   }
   disk_cache_destroy(cache);

   cache = disk_cache_create("test", "make_check", 0);
   EXPECT_TRUE(cache_exists(cache))
      << "disk_cache_create with XDG_CACHE_HOME set";

   char *path = ralloc_asprintf(
      mem_ctx, "%s%s", CACHE_TEST_TMP "/xdg-cache-home/", cache_dir_name);
   check_directories_created(mem_ctx, path);

   disk_cache_destroy(cache);

   /* Test with MESA_SHADER_CACHE_DIR set */
   err = rmrf_local(CACHE_TEST_TMP);
   EXPECT_EQ(err, 0) << "Removing " CACHE_TEST_TMP;

   setenv("MESA_SHADER_CACHE_DIR", CACHE_TEST_TMP "/mesa-shader-cache-dir", 1);
   cache = disk_cache_create("test", "make_check", 0);
   EXPECT_FALSE(cache_exists(cache))
      << "disk_cache_create with MESA_SHADER_CACHE_DIR set with a non-existing parent directory";

   err = mkdir(CACHE_TEST_TMP, 0755);
   if (err != 0) {
      fprintf(stderr, "Error creating %s: %s\n", CACHE_TEST_TMP, strerror(errno));
      GTEST_FAIL();
   }
   disk_cache_destroy(cache);

   cache = disk_cache_create("test", "make_check", 0);
   EXPECT_TRUE(cache_exists(cache)) << "disk_cache_create with MESA_SHADER_CACHE_DIR set";

   path = ralloc_asprintf(
      mem_ctx, "%s%s", CACHE_TEST_TMP "/mesa-shader-cache-dir/", cache_dir_name);
   check_directories_created(mem_ctx, path);

   disk_cache_destroy(cache);
}

static void
test_put_and_get(bool test_cache_size_limit)
{
   struct disk_cache *cache;
   char blob[] = "This is a blob of thirty-seven bytes";
   uint8_t blob_key[20];
   char string[] = "While this string has thirty-four";
   uint8_t string_key[20];
   char *result;
   size_t size;
   uint8_t *one_KB, *one_MB;
   uint8_t one_KB_key[20], one_MB_key[20];
   int count;

#ifdef SHADER_CACHE_DISABLE_BY_DEFAULT
   setenv("MESA_SHADER_CACHE_DISABLE", "false", 1);
#endif /* SHADER_CACHE_DISABLE_BY_DEFAULT */

   cache = disk_cache_create("test", "make_check", 0);

   disk_cache_compute_key(cache, blob, sizeof(blob), blob_key);

   /* Ensure that disk_cache_get returns nothing before anything is added. */
   result = (char *) disk_cache_get(cache, blob_key, &size);
   EXPECT_EQ(result, nullptr) << "disk_cache_get with non-existent item (pointer)";
   EXPECT_EQ(size, 0) << "disk_cache_get with non-existent item (size)";

   /* Simple test of put and get. */
   disk_cache_put(cache, blob_key, blob, sizeof(blob), NULL);

   /* disk_cache_put() hands things off to a thread so wait for it. */
   disk_cache_wait_for_idle(cache);

   result = (char *) disk_cache_get(cache, blob_key, &size);
   EXPECT_STREQ(blob, result) << "disk_cache_get of existing item (pointer)";
   EXPECT_EQ(size, sizeof(blob)) << "disk_cache_get of existing item (size)";

   free(result);

   /* Test put and get of a second item. */
   disk_cache_compute_key(cache, string, sizeof(string), string_key);
   disk_cache_put(cache, string_key, string, sizeof(string), NULL);

   /* disk_cache_put() hands things off to a thread so wait for it. */
   disk_cache_wait_for_idle(cache);

   result = (char *) disk_cache_get(cache, string_key, &size);
   EXPECT_STREQ(result, string) << "2nd disk_cache_get of existing item (pointer)";
   EXPECT_EQ(size, sizeof(string)) << "2nd disk_cache_get of existing item (size)";

   free(result);

   /* Set the cache size to 1KB and add a 1KB item to force an eviction. */
   disk_cache_destroy(cache);

   if (!test_cache_size_limit)
      return;

   setenv("MESA_SHADER_CACHE_MAX_SIZE", "1K", 1);
   cache = disk_cache_create("test", "make_check", 0);

   one_KB = (uint8_t *) calloc(1, 1024);

   /* Obviously the SHA-1 hash of 1024 zero bytes isn't particularly
    * interesting. But we do have want to take some special care with
    * the hash we use here. The issue is that in this artificial case,
    * (with only three files in the cache), the probability is good
    * that each of the three files will end up in their own
    * directory. Then, if the directory containing the .tmp file for
    * the new item being added for disk_cache_put() is the chosen victim
    * directory for eviction, then no suitable file will be found and
    * nothing will be evicted.
    *
    * That's actually expected given how the eviction code is
    * implemented, (which expects to only evict once things are more
    * interestingly full than that).
    *
    * For this test, we force this signature to land in the same
    * directory as the original blob first written to the cache.
    */
   disk_cache_compute_key(cache, one_KB, 1024, one_KB_key);
   one_KB_key[0] = blob_key[0];

   disk_cache_put(cache, one_KB_key, one_KB, 1024, NULL);

   free(one_KB);

   /* disk_cache_put() hands things off to a thread so wait for it. */
   disk_cache_wait_for_idle(cache);

   result = (char *) disk_cache_get(cache, one_KB_key, &size);
   EXPECT_NE(result, nullptr) << "3rd disk_cache_get of existing item (pointer)";
   EXPECT_EQ(size, 1024) << "3rd disk_cache_get of existing item (size)";

   free(result);

   /* Ensure eviction happened by checking that both of the previous
    * cache itesm were evicted.
    */
   bool contains_1KB_file = false;
   count = 0;
   if (does_cache_contain(cache, blob_key))
       count++;

   if (does_cache_contain(cache, string_key))
       count++;

   if (does_cache_contain(cache, one_KB_key)) {
      count++;
      contains_1KB_file = true;
   }

   EXPECT_TRUE(contains_1KB_file)
      << "disk_cache_put eviction last file == MAX_SIZE (1KB)";
   EXPECT_EQ(count, 1) << "disk_cache_put eviction with MAX_SIZE=1K";

   /* Now increase the size to 1M, add back both items, and ensure all
    * three that have been added are available via disk_cache_get.
    */
   disk_cache_destroy(cache);

   setenv("MESA_SHADER_CACHE_MAX_SIZE", "1M", 1);
   cache = disk_cache_create("test", "make_check", 0);

   disk_cache_put(cache, blob_key, blob, sizeof(blob), NULL);
   disk_cache_put(cache, string_key, string, sizeof(string), NULL);

   /* disk_cache_put() hands things off to a thread so wait for it. */
   disk_cache_wait_for_idle(cache);

   count = 0;
   if (does_cache_contain(cache, blob_key))
       count++;

   if (does_cache_contain(cache, string_key))
       count++;

   if (does_cache_contain(cache, one_KB_key))
       count++;

   EXPECT_EQ(count, 3) << "no eviction before overflow with MAX_SIZE=1M";

   /* Finally, check eviction again after adding an object of size 1M. */
   one_MB = (uint8_t *) calloc(1024, 1024);

   disk_cache_compute_key(cache, one_MB, 1024 * 1024, one_MB_key);
   one_MB_key[0] = blob_key[0];

   disk_cache_put(cache, one_MB_key, one_MB, 1024 * 1024, NULL);

   free(one_MB);

   /* disk_cache_put() hands things off to a thread so wait for it. */
   disk_cache_wait_for_idle(cache);

   bool contains_1MB_file = false;
   count = 0;
   if (does_cache_contain(cache, blob_key))
       count++;

   if (does_cache_contain(cache, string_key))
       count++;

   if (does_cache_contain(cache, one_KB_key))
       count++;

   if (does_cache_contain(cache, one_MB_key)) {
      count++;
      contains_1MB_file = true;
   }

   EXPECT_TRUE(contains_1MB_file)
      << "disk_cache_put eviction last file == MAX_SIZE (1MB)";
   EXPECT_EQ(count, 1) << "eviction after overflow with MAX_SIZE=1M";

   disk_cache_destroy(cache);
}

static void
test_put_key_and_get_key(void)
{
   struct disk_cache *cache;
   bool result;

   uint8_t key_a[20] = {  0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
                         10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
   uint8_t key_b[20] = { 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
                         30, 33, 32, 33, 34, 35, 36, 37, 38, 39};
   uint8_t key_a_collide[20] =
                        { 0,  1, 42, 43, 44, 45, 46, 47, 48, 49,
                         50, 55, 52, 53, 54, 55, 56, 57, 58, 59};

#ifdef SHADER_CACHE_DISABLE_BY_DEFAULT
   setenv("MESA_SHADER_CACHE_DISABLE", "false", 1);
#endif /* SHADER_CACHE_DISABLE_BY_DEFAULT */

   cache = disk_cache_create("test", "make_check", 0);

   /* First test that disk_cache_has_key returns false before disk_cache_put_key */
   result = disk_cache_has_key(cache, key_a);
   EXPECT_EQ(result, 0) << "disk_cache_has_key before key added";

   /* Then a couple of tests of disk_cache_put_key followed by disk_cache_has_key */
   disk_cache_put_key(cache, key_a);
   result = disk_cache_has_key(cache, key_a);
   EXPECT_EQ(result, 1) << "disk_cache_has_key after key added";

   disk_cache_put_key(cache, key_b);
   result = disk_cache_has_key(cache, key_b);
   EXPECT_EQ(result, 1) << "2nd disk_cache_has_key after key added";

   /* Test that a key with the same two bytes as an existing key
    * forces an eviction.
    */
   disk_cache_put_key(cache, key_a_collide);
   result = disk_cache_has_key(cache, key_a_collide);
   EXPECT_EQ(result, 1) << "put_key of a colliding key lands in the cache";

   result = disk_cache_has_key(cache, key_a);
   EXPECT_EQ(result, 0) << "put_key of a colliding key evicts from the cache";

   /* And finally test that we can re-add the original key to re-evict
    * the colliding key.
    */
   disk_cache_put_key(cache, key_a);
   result = disk_cache_has_key(cache, key_a);
   EXPECT_EQ(result, 1) << "put_key of original key lands again";

   result = disk_cache_has_key(cache, key_a_collide);
   EXPECT_EQ(result, 0) << "put_key of orginal key evicts the colliding key";

   disk_cache_destroy(cache);
}

/* To make sure we are not just using the inmemory cache index for the single
 * file cache we test adding and retriving cache items between two different
 * cache instances.
 */
static void
test_put_and_get_between_instances()
{
   char blob[] = "This is a blob of thirty-seven bytes";
   uint8_t blob_key[20];
   char string[] = "While this string has thirty-four";
   uint8_t string_key[20];
   char *result;
   size_t size;

#ifdef SHADER_CACHE_DISABLE_BY_DEFAULT
   setenv("MESA_SHADER_CACHE_DISABLE", "false", 1);
#endif /* SHADER_CACHE_DISABLE_BY_DEFAULT */

   struct disk_cache *cache1 = disk_cache_create("test_between_instances",
                                                 "make_check", 0);
   struct disk_cache *cache2 = disk_cache_create("test_between_instances",
                                                 "make_check", 0);

   disk_cache_compute_key(cache1, blob, sizeof(blob), blob_key);

   /* Ensure that disk_cache_get returns nothing before anything is added. */
   result = (char *) disk_cache_get(cache1, blob_key, &size);
   EXPECT_EQ(result, nullptr) << "disk_cache_get(cache1) with non-existent item (pointer)";
   EXPECT_EQ(size, 0) << "disk_cache_get(cach1) with non-existent item (size)";

   result = (char *) disk_cache_get(cache2, blob_key, &size);
   EXPECT_EQ(result, nullptr) << "disk_cache_get(cache2) with non-existent item (pointer)";
   EXPECT_EQ(size, 0) << "disk_cache_get(cache2) with non-existent item (size)";

   /* Simple test of put and get. */
   disk_cache_put(cache1, blob_key, blob, sizeof(blob), NULL);

   /* disk_cache_put() hands things off to a thread so wait for it. */
   disk_cache_wait_for_idle(cache1);

   result = (char *) disk_cache_get(cache2, blob_key, &size);
   EXPECT_STREQ(blob, result) << "disk_cache_get(cache2) of existing item (pointer)";
   EXPECT_EQ(size, sizeof(blob)) << "disk_cache_get of(cache2) existing item (size)";

   free(result);

   /* Test put and get of a second item, via the opposite instances */
   disk_cache_compute_key(cache2, string, sizeof(string), string_key);
   disk_cache_put(cache2, string_key, string, sizeof(string), NULL);

   /* disk_cache_put() hands things off to a thread so wait for it. */
   disk_cache_wait_for_idle(cache2);

   result = (char *) disk_cache_get(cache1, string_key, &size);
   EXPECT_STREQ(result, string) << "2nd disk_cache_get(cache1) of existing item (pointer)";
   EXPECT_EQ(size, sizeof(string)) << "2nd disk_cache_get(cache1) of existing item (size)";

   free(result);

   disk_cache_destroy(cache1);
   disk_cache_destroy(cache2);
}
#endif /* ENABLE_SHADER_CACHE */

class Cache : public ::testing::Test {
protected:
   void *mem_ctx;

   Cache() {
      mem_ctx = ralloc_context(NULL);
   }
   ~Cache() {
      ralloc_free(mem_ctx);
   }
};

TEST_F(Cache, MultiFile)
{
#ifndef ENABLE_SHADER_CACHE
   GTEST_SKIP() << "ENABLE_SHADER_CACHE not defined.";
#else
   test_disk_cache_create(mem_ctx, CACHE_DIR_NAME);

   test_put_and_get(true);

   test_put_key_and_get_key();

   int err = rmrf_local(CACHE_TEST_TMP);
   EXPECT_EQ(err, 0) << "Removing " CACHE_TEST_TMP " again";
#endif
}

TEST_F(Cache, SingleFile)
{
#ifndef ENABLE_SHADER_CACHE
   GTEST_SKIP() << "ENABLE_SHADER_CACHE not defined.";
#else
   setenv("MESA_DISK_CACHE_SINGLE_FILE", "true", 1);

   test_disk_cache_create(mem_ctx, CACHE_DIR_NAME_SF);

   /* We skip testing cache size limit as the single file cache currently
    * doesn't have any functionality to enforce cache size limits.
    */
   test_put_and_get(false);

   test_put_key_and_get_key();

   test_put_and_get_between_instances();

   setenv("MESA_DISK_CACHE_SINGLE_FILE", "false", 1);

   int err = rmrf_local(CACHE_TEST_TMP);
   EXPECT_EQ(err, 0) << "Removing " CACHE_TEST_TMP " again";
#endif
}
